<?php 
function name (){
    
    echo "toi la vo tuan anh";
    echo "trung sy bo bo tu lenh thong tin";
    }
    name();


?>

<?php
 
function binhphuong($num) {
    $bien = $num * $num;
    return $bien . "<br ?-->";
}
 
echo "binh phuong cua 5 la" . binhphuong(5);
echo "binh phuong cua 10 la " . binhphuong(10);
echo "binh phuong cua 15 la : " . binhphuong(15)
 
?>